Controlling legend labels for a plot with color and linetype aesthetic attributes

Question

I would like to plot four lines with the legend label AND color dictated by unique values in the column, "Color_Group" and the linetype by "Line_Type_Group". Here is code needed to make the data frame, and the data frame itself.

data <- data.frame("x"=c(1,2,1,2,1,2,1,2),
                "y"=1:8,
                "Color_Group"=c("A","A","A","A","B","B","C","C"),
                "Line_Type_Group"=c(1,1,2,2,2,2,1,1),
                "Group"=c("A1","A1","A2","A2","B2","B2","C1","C1"),
                stringsAsFactors=F)

> data
  x y Color_Group Line_Type_Group  Group
  1 1           A               1     A1
  2 2           A               1     A1
  1 3           A               2     A2
  2 4           A               2     A2
  1 5           B               2     B2
  2 6           B               2     B2
  1 7           C               1     C1
  2 8           C               1     C1

The main "Group" column is the result of pasting the color and linetype columns together, and it represents the id for each line. In order to get one legend, I initially map the color and linetype attributes to this "Group" column. Below is what I want the plot to look like.

Desired Plot

Attempt

For simplicity's sake, I'm recreating the data frame to include columns with the literal color and linetype values.

data <- data.frame("x"=c(1,2,1,2,1,2,1,2),
                "y"=1:8,"Color_Group"=c("A","A","A","A","B","B","C","C"),
                "Color"=c(rep("red",4),"blue","blue","green","green"),
                "Line_Type_Group"=c(1,1,2,2,2,2,1,1),
                "Line_Type"=c("solid","solid","dashed","dashed","dashed","dashed","solid","solid"),
                "Group"=c("A1","A1","A2","A2","B2","B2","C1","C1"),
                stringsAsFactors = F)

> data
  x y Color_Group Color Line_Type_Group Line_Type Group
  1 1           A   red               1     solid    A1
  2 2           A   red               1     solid    A1
  1 3           A   red               2    dashed    A2
  2 4           A   red               2    dashed    A2
  1 5           B  blue               2    dashed    B2
  2 6           B  blue               2    dashed    B2
  1 7           C green               1     solid    C1
  2 8           C green               1     solid    C1  


line_type_group <- data$Line_Type
color_group <- data$Color
names(line_type_group) <- data$Group
names(color_group) <- data$Group
labels <- data$Color_Group
names(labels) <- data$Group
#Both attempts at setting labels variable yields plot below
#labels <- c("A","A","B","C")

g <- ggplot(data,aes(x=x,y=y,colour=Group,linetype=Group))+geom_line()
g + scale_colour_manual(name="Legend",values=color_group,labels=labels) +
    scale_linetype_manual(name="Legend",values =line_type_group,labels=labels)

Answer 1

You could work around this by suppressing the linetype legend after changing the values to what you want and then "manually" setting the linetypes in the colour legend using override.aes .

ggplot(data,aes(x=x, y=y, colour=Group, linetype=Group))+
    geom_line() + 
    scale_colour_manual(values = color_group, labels = labels) +
    scale_linetype_manual(values = line_type_group, guide = "none") +
    guides(colour = guide_legend(override.aes = list(linetype = c(1, 2, 2, 1))))

Answer 2

this give you almost what you want

g <- ggplot(data,aes(x=x,y=y,colour=Group,linetype=Group))+geom_line()
g + scale_colour_manual(name="Legend",values=c("red", "red", "blue", "green"), labels = c("A1", "A2", "B", "C")) +scale_linetype_manual(name="Legend",values=c("solid", "dashed", "dashed", "solid"), labels = c("A1", "A2", "B", "C"))
#
g